1. Field of the Invention
The present invention generally relates to information processing apparatuses, information processing methods, and recording media. More particularly, the invention relates to an information processing apparatus which is connected to other information processing apparatuses via an IEEE-1394 serial data bus and which reliably and individually controls built-in sub-units. The invention also pertains to an information processing method used in the above type of information processing apparatus and to a recording medium implementing this method.
2. Description of the Related Art
Audio/visual (AV) machines that can transmit information to each other via a network using an IEEE-1394 serial data bus are being developed. In this network, it is possible to control the AV machines connected to the network by using a predetermined command (AV/C Command Transaction Set). For example, a video picture received by an Integrated Receiver Decoder (IRD) 71 for receiving digital satellite broadcasts can be recorded, as shown in FIG. 1, on a Digital Video Cassette Recorder (DVCR) 81 connected to the IRD 71 via an IEEE-1394 serial data bus 2 (hereinafter simply referred to as the xe2x80x9cbus 2xe2x80x9d). Additionally, what is called xe2x80x9crecording reservationsxe2x80x9d can be made by using the IRD 71 and the DVCR 81.
According to the recording reservation processing, a controller 72 of the IRD 71 controls the IRD 71 and the DVCR 81. More specifically, the recording-reservation settings (channel, recording start time, etc.) are made on the IRD 71, and when the recording start time is reached, the controller 72 of the IRD 71 controls a tuner sub-unit 73 to select the reserved (set) channel and to output a received video signal to the DVCR 81 via the bus 2. Simultaneously, the controller 72 transmits a recording start command to a VCR sub-unit 84 of the DVCR 81 via the bus 2. In response to the recording start command transmitted from the controller 72, the VCR sub-unit 84 of the DVCR 81 records the video signal supplied from the tuner sub-unit 73 on magnetic tape (not shown).
As discussed above, it is possible to control the operation of the DVCR 81 from another machine (in the example shown in FIG. 1, the IRD 71) connected to the DVCR 81 via the bus 2. In this case, there may be a danger that what is called xe2x80x9cdouble-bookingxe2x80x9d occurs.
For example, when a recording reservation (recording reservation A) of a digital satellite broadcast is input into the IRD 71, the reservation information is stored in the controller 72 of the IRD 71. Thereafter, if a recording reservation (recording reservation B) of a terrestrial analog broadcast, which is to be broadcast at the same time as the recording reservation A, is input into the DVCR 81, a controller 82 of the DVCR 81 receives and stores the recording reservation B since the information concerning the recording reservation A input into the IRD 71 has not been reported to the DVCR 81. Thus, upon reaching the time when both the recording reservation A and the recording reservation B are started, video pictures are inconveniently supplied from both the tuner sub-unit 73 of the IRD 71 and an analog tuner block 83 of the DVCR 81 to the VCR sub-unit 84 of the DVCR 81.
The above inconvenience originates from the fact that reservation information managed by an AV machine is not available for another AV machine connected via the bus 2.
In order to overcome the above-described drawback, a CS mode is conventionally provided for the DVCR 81. According to the CS mode, the DVCR 81 is controlled only by the controller 72 of the IRD 71 and enters the recording standby position. After the recording reservation A is input into the IRD 71, the DVCR 81 is set in the CS mode, thereby preventing the occurrence of double-hooking.
However, since the DVCR 81 set in the CS mode goes into the reservation standby position, it cannot execute processing, such as reproduction of video signals, thereby decreasing the ease of operation.
Further, information (recording start time, etc.) managed by an AV machine is not reported to the other AV machines. Because of this, when the AV machines simultaneously output information to the bus 2, the amount of information may exceed the bandwidth of the bus 2, causing transmission errors to occur.
Accordingly, in view of the above background, it is an object of the present invention to improve the ease of reserve-recording operation and to inhibit the occurrence of double-booking by mutually searching information managed by the individual AV machines connected to a bus.
In order to achieve the above object, according to one aspect of the present invention, there is provided an information processing apparatus including an input unit for inputting reservation information concerning a reservation of the sub-unit. A storage unit stores the reservation information concerning the reservation of the sub-unit. A supply unit reads out the reservation information stored in the storage unit and supplies the reservation information to an external information processing apparatus in response to a request from the external information processing apparatus.
The aforementioned information processing apparatus may further include a write unit for writing the reservation information of the sub-unit of the information processing apparatus into the storage unit and for writing reservation information of a sub-unit of the external information processing apparatus into a storage unit of the external information processing apparatus when a reservation is made for using the sub-unit of the information processing apparatus in cooperation with the sub-unit of the external information processing apparatus at the same time.
The aforementioned information processing apparatus may further include a comparison unit for comparing the reservation information input by the input unit with the reservation information stored in the storage unit of the information processing apparatus and the reservation information of the storage unit of the external information processing apparatus including the sub-unit to be used at the same time as the sub-unit of the information processing apparatus. Accordingly, the writing means may write the reservation information in accordance with a comparison result obtained by the comparison unit.
The write unit may restrict the reservation information to be written into the storage unit of the information processing apparatus from the external information storage apparatus when the writing means writes the reservation information into the storage unit of the information processing apparatus.
The write unit may interrupt the external information processing apparatus from reading the reservation information from the storage unit of the information processing apparatus when the write unit writes the reservation information into the storage unit of the information processing apparatus.
The storage unit may store limitation information concerning a limitation of the reservation information to be stored, and the supply unit may supply the limitation information to the external information processing apparatus in response to a request form the external information processing apparatus.
The storage unit may store the reservation information at a predetermined address position.
The reservation information may include a sub-unit start time at which the use of the sub-unit is started and a period for using the sub-unit. The period for using the sub-unit may be set as an undefined value.
The reservation information may include apparatus information concerning the information processing apparatus that reserves the sub-unit, and the apparatus information may be stored at an address position subsequent to the address positions of the sub-unit start time and the period for using the sub-unit. The sub-unit start time may be represented by a binary-coded decimal (BCD).
The storage unit may further store identification information for identifying the stored reservation information.
The identification information may include a value unique to the information processing apparatus that has reserved the sub-unit and a value unique to the reservation set in the information processing apparatus.
The value unique to the information processing apparatus may be a global unique ID, and the value unique to the reservation may be a record ID.
The reservation information may include weekly reservation information of the sub-unit that is weekly reserved by specifying a day of the week.
The reservation information may include interval reservation information of the sub-unit that is repeatedly reserved at a predetermined interval.
The storage unit may be one of the sub-units.
The network may be formed by using an IEEE-1394 serial data bus.
According to another aspect of the present invention, there is provided an information processing method for use in an information processing apparatus. The information processing method includes an input step of inputting reservation information concerning a reservation of a sub-unit, a storage control step of controlling storage of the reservation information concerning the reservation of the sub-unit, and a supply step of reading out the reservation information stored by processing of the storage control step and of supplying the reservation information to an external information processing apparatus in response to a request from the external information processing apparatus.
According to still another aspect of the present invention, there is provided a recording medium for recording a program for controlling an information processing apparatus. The program includes an input step of inputting reservation information concerning a reservation of a sub-unit, a storage control step of controlling storage of the reservation information concerning the reservation of the sub-unit, and a supply step of reading out the reservation information stored by processing of the storage control step and of supplying the reservation information to an external information processing apparatus in response to a request from the external information processing apparatus.
According to the information processing apparatus, the information processing method, and the recording medium, the reservation information concerning a reservation of a sub-unit is stored, and in response to a request from an external information processing apparatus, the stored reservation information is supplied to the external information processing apparatus.